In my experience every time I have flashed a new ROM or a kernel/theme I have had to do this, fyi.
Download Root Explorer - paid app (worth the money)
or use Estrongs file explorer which is free but using the root "tools" that enable you to write in the desired file will break the app and you'll have to re-install to be able to use it again
in the /system folder edit the build.prop file.
scroll down to the line that says:
media.stagefright.enable-player=true
change the true to a false and save the file.
sometimes i have found that a reboot is helpful but not necessary.
I don't hold Sirius as a company in very high regard and decided to root my phone and take matters in my own hands. I have no idea why it's taking so long to develop and fix this app, there are some other underlying issues to it in regards to the overall quality of audio on the android system.
here's a good post explaing the issues:
Fix coming for Froyo audio issues | Android Central